The Orion spacecraft and Altair lunar lander intended for a manned Moon mission are large craft that would require a heavy lift launcher for the trip. However the Dragon capsule is a smaller capsule that would allow lunar missions with currently existing launchers. The idea for this use would be for it to act as a reusable shuttle only between LEO and the lunar surface. This page gives the dry mass of the Dragon capsule of 3,180 kg:

The wet mass with propellant would be higher than this but for use only as a shuttle between LEO and the Moon, the engines and propellant would be taken up by the attached propulsion system. With crew and supplies call the capsule mass 4,000 kg. On this listing of space vehicles you can find that the later versions of the Centaur upper stage have a mass ratio of about 10 to 1:

The architecture will be to use a larger Centaur upper stage to serve as the propulsion system to take the vehicle from LEO to low lunar orbit. This larger stage will not descend to the surface, but will remain in orbit. A smaller Centaur stage will serve as the descent stage and will also serve as the liftoff stage that will take the spacecraft not just back to lunar orbit, but all the way to back to LEO. The larger Centaur stage will return to LEO under its own propulsion, to make the system fully reusable. Both stages will use aerobraking to reduce the delta-V required to return to LEO. For the larger Centaur, take the gross mass of the stage alone as 30,000 kg, and its dry mass as 1/10th of that at 3,000 kg. For the smaller Centaur stage take the gross mass as 10,000 kg and the dry mass as 1,000 kg. The "Delta-V budget" page gives the delta-V from LEO to low lunar orbit as 4,040 m/s. In calculating the delta-V provided by the larger Centaur stage we'll retain 1,000 kg propellant at the end of the burn for the return trip of this stage to LEO: 465.5*9.8ln((30,000 + 10,000 + 4,000)/(3,000 +10,000 + 4,000 + 1,000)) = 4,077 m/s, sufficient to reach low lunar orbit. For this stage alone to return to LEO, 1,310 m/s delta-V is required. The 1,000 kg retained propellant provides 465.5*9.8ln((3,000 + 1,000)/3,000) = 1,312 m/s, sufficient for the return. The delta-V to go from low lunar orbit to the Moon's surface is 1,870 m/s. And to go from the Moon's surface back to LEO is 2,740 m/s, for a total of 4,610 m/s. The delta-V provided by this smaller Centaur stage is 465.5*9.8ln((10,000 + 4,000)/(1,000 + 4,000)) = 4,697 m/s, sufficient for lunar landing and the return to LEO. The RL-10 engine was proven to be reusable for multiple uses with quick turnaround time on the DC-X. The total propellant load of 40,000 kg could be lofted by two 20,000+ kg payload capacity launchers, such as the Atlas V, Delta IV Heavy, Ariane 5, and Proton. The price for these launchers is in the range of $100-140 million according to the specifications on this page:

So two would be in the range of $200-$280 million. The Dragon spacecraft and Centaur stages being reusable for 10+ uses would mean their cost per flight should be significantly less than this. This would bring the cost into the range affordable to be purchased by most national governments. Still, it would be nice to reduce that $200 million cost just to bring the propellant to orbit. One possibility might be the heavy lift launchers being planned by NASA. One of the main problems in deciding on a design for the launchers is that there would be so few launches the per launch cost would be too high. However, launching of the propellant to orbit for lunar missions would provide a market that could allow multiple launches per year thus reducing the per launch cost of the heavy lift launchers. For instance, the Direct HLV team claims their launcher would cost $240 million per launch if they could make 12 launches per year:

This launcher would have a 70,000 kg payload capacity. However, if you removed the payload fairing and interstage and just kept the propellant to be launched to orbit in the ET itself and considering the fact that the shuttle system was able to launch 100,000+ kg to orbit with the shuttle and payload, it's possible the propellant that could be launched to orbit could be in the range of 100,000 kg. Then the cost per kg to orbit would be $2,400 per kg, or about a $100 million cost for the propellant to orbit. Reduction of the per launch cost for the heavy lift launchers would then allow affordable launches of the larger spacecraft and landers for lunar missions.

Bob Clark

_________________Nanotechnology now can produce the space elevator and private orbital launchers. It now also makes possible the long desired 'flying cars'. This crowdfunding campaign is to prove it:

Especially innovative about this design is the "parashield" thermal protection. Not only is this lightweight but another advantage is that it has a higher protective area so that you can use a larger volume cylindrical structure rather than the usual conical structure for the capsule. As with the Orion CEV, this Phoenix spacecraft was intended to be used in conjunction with a separate lander for lunar missions. However, by using it both for the trip from LEO and as the lander you get great savings in cost. On page 3 of the report is given a breakdown of the weights of the various subsystems. By removing the propulsion system as I suggested for the Dragon for this purpose, the mass with crew would be about half that of the Dragon, at about 2,000 kg. Then assuming again 10 to 1 mass ratios for two Centaur style stages for propulsion, we would need about half the mass for propulsion and propellant as for the Dragon, about 20,000 kg, which could be lofted by a single launch of the current largest launchers. Then the cost of lofting this propellant load to LEO would be about $100 million. And if a new heavy lift launcher could get a $2,400 per kg launch price, it would only be in the range of $50 million. This would increase even further the market for such low cost lunar missions.

Bob Clark

_________________Nanotechnology now can produce the space elevator and private orbital launchers. It now also makes possible the long desired 'flying cars'. This crowdfunding campaign is to prove it:

The Phoenix paper is interesting, but has a couple of technical issues that jump right out. The wide spacing on the motors might make for a convenient compact configuration, but presents a terminal single point of failure if you have a motor failure or asymmetric output unless the motor has a really wide gimbal range (45?). I also doubt the ISS folks would appreciate having rocket motors pointed at their station for long periods of time...

Has a collapsing "parashield" ever been flight tested? Seems like a clever idea, but I have doubts about the erosion/ablation and stress loading that it would experience in a real re-entry.

The Falcon 9 Heavy is estimated to be able to orbit ~34 tons, which could be carried in the tanks of a modified Second Stage. Enough to push a Dragon around the Moon and back.

Or orbit two tankers and push a separate lander to the Moon for the ride to the surface. I'm not so sure of that table's figures on delta-vee to the Moon's surface since the Apollos typically needed ~2,000 m/s to land. While a direct return is in theory possible it means landing more gas to the surface and can be less effective than keeping lander and return vehicle separate.

The price for these commercial lunar flights could be cut dramatically if instead of hauling the fuel from the Earth, it could be obtained from the Moon. This would require automated systems to produce propellant from the materials on the Moon.Then as a precursor to show this is feasible it would be necessary to do a smaller unmanned lunar lander mission that demonstrates ISRU propellant production. We will want to do a reusable, round trip mission to also show the feasibility of the manned missions. However, as a low cost first step we'll only do an expendable one-way lander that drops off an electrolysis station to produce hydrogen/oxygen from the water found by LCROSS to be near surface in the polar regions.To keep costs low we'll use the Russian Dnepr rocket:

According to this page, the price is $10-$13 million for up to 4,500 kg to LEO. So we'll need to keep the total mass for the lander and the propulsion system under 4,500 kg.One possibility for the propulsion might be the solid motor "Star" series, but multiply staged. Find the specifications for the Star 48 version here:

They have a good mass ratio at around 18 or 19 to 1. And a moderate Isp, from 286 s to 292 s. However, it should be noted that the low dry mass indicated, which results in the high mass ratio, is coming from the fact this is only considering the nozzle and casing. Reaction control thrusters and the avionics assemblies are not included in this dry mass.A more accurate accounting for the dry mass for this upper stage might be here:

Note this page, with the higher dry mass, indicates this upper stage with the Star 48 engine does also use reaction control thrusters. The extra mass was about 100 kg added onto the 111 kg Star 48 bare mass. I'll reserve 100 kg for the RCS and avionics within the mass of the payload, and use the bare masses for the Star engines in the delta-V calculations. The final, smallest stage will have slightly more powerful RCS than needed and for the lower stages I'll rely on spin-stabilization and the upper stage RCS for stability while the lower stage motors are firing.Let's calculate how much payload we could deliver to the Moon's surface. This page gives the delta-V requirements in the Earth-Moon system:

To get to the lunar surface from LEO would require a delta-V of 5.93 km/s. The stages used will be the Star 48B, the Star 37FM, and the Star 30. Estimate the payload to the Moon as 400 kg. The delta-V needed for Trans Lunar Injection will be in the range of 3.05 to 3.25 km/s. The delta-V you could get from the Star 48 first stage would be: 286*9.8ln((2134.3+1148+492+400)/(111.3+1148+492+400)) = 1,857 m/s.The delta-V you get from the Star 37FM second stage will be: 289.9*9.8ln((1,148+492+400)/(73.7+492+400)) = 2,125 m/s. The two lower stages give you a total of 3,982 m/s, sufficient for TLI.You need now 5,930 - 3,982 = 1,948 m/s additional delta-V to complete the landing. The delta-V you get from the Star 30 will be: 293*9.8ln((492+400)/(28+400)) = 2,109 m/s, sufficient for the landing.The total gross mass of the 3 stages plus payload will be 2,134.3+1,148+492+400 = 4,174.3 kg, within the lift capacity of the Dnepr 1. The cost of the Dnepr 1 might be $13 million. The costs of the upper stages? The Astronautix page on the PAM-S powered by the Star 48 motor gives the price as $4.06 million. The Star 37 is smaller by half, and the Star 30 is smaller by an additional factor of one-half. Then we might estimate their prices as $2 million and $1 million respectively, for a total cost of these upper stages of $7 million. Then the total launch cost might be $20 million.We would have to add onto that the cost of the avionics and the cost of the lander.

Bob Clark

_________________Nanotechnology now can produce the space elevator and private orbital launchers. It now also makes possible the long desired 'flying cars'. This crowdfunding campaign is to prove it:

...To get to the lunar surface from LEO would require a delta-V of 5.93 km/s. The stages used will be the Star 48B, the Star 37FM, and the Star 30. Estimate the payload to the Moon as 400 kg. The delta-V needed for Trans Lunar Injection will be in the range of 3.05 to 3.25 km/s. The delta-V you could get from the Star 48 first stage would be: 286*9.8ln((2134.3+1148+492+400)/(111.3+1148+492+400)) = 1,857 m/s.The delta-V you get from the Star 37FM second stage will be: 289.9*9.8ln((1,148+492+400)/(73.7+492+400)) = 2,125 m/s. The two lower stages give you a total of 3,982 m/s, sufficient for TLI.You need now 5,930 - 3,982 = 1,948 m/s additional delta-V to complete the landing. The delta-V you get from the Star 30 will be: 293*9.8ln((492+400)/(28+400)) = 2,109 m/s, sufficient for the landing.The total gross mass of the 3 stages plus payload will be 2,134.3+1,148+492+400 = 4,174.3 kg, within the lift capacity of the Dnepr 1. The cost of the Dnepr 1 might be $13 million. The costs of the upper stages? The Astronautix page on the PAM-S powered by the Star 48 motor gives the price as $4.06 million. The Star 37 is smaller by half, and the Star 30 is smaller by an additional factor of one-half. Then we might estimate their prices as $2 million and $1 million respectively, for a total cost of these upper stages of $7 million. Then the total launch cost might be $20 million.We would have to add onto that the cost of the avionics and the cost of the lander.

As a point of comparison about the feasibility of using solid motor upper stages for the purpose, the Dnepr has been studied to be used to launch a 500 kg payload to GEO by using two Star solid motor upper stages and lunar gravity assist:

Dnepr (R-36M2). "The Dnepr launch vehicle does not have the capability to deploy payloads directiy into GTO. However, Kosmotras has studied a technique to deliver small spacecraft to GEO using the gravity of the Moon to provide the plane change and perigee raising. In this scenario, the spacecraft is attached to Star 48A and Star 27 solid motors, supplied separately by ATK Thiokol. The Star48A would send the spacecraft to the Moon, where a gravity slingshot maneuver would lower the transfer orbit inclination from 50.5 deg to 0 deg, and raise the orbit perigee to geostationary altitude. When the spacecraft reaches perigee of the new transfer orbit, the Star 27 motor would fire to circularize the orbit at GEO. Using this method, a 500 kg (1100 lbm) spacecraft could be delivered to GEO."http://www.b14643.de/Spacerockets_1/Eas ... /Frame.htm

Bob Clark

_________________Nanotechnology now can produce the space elevator and private orbital launchers. It now also makes possible the long desired 'flying cars'. This crowdfunding campaign is to prove it:

About 12 minutes in, one of the panel members made an interesting comparison between what is considered to be a profitable mine on Earth and what the LCROSS data suggests is available near surface in some shadowed craters on the Moon. He said a mine on Earth might be profitable if you can make in the range of $150 per ton of material excavated. But judging from the LCROSS data, the minerals available in shadowed craters might value in the range of $1,000,000 per ton of excavated material. This might be sufficient justification for some mining companies to pay for a low cost exploratory lander mission. For instance the Dnepr rocket can lift 550 kg to TLI at a cost of $10 to $13 million. This might be sufficient mass for a lander with a descent rocket with just simple instruments such as a APXS and infrared spectrometers and radio transmission capability.

Bob Clark

_________________Nanotechnology now can produce the space elevator and private orbital launchers. It now also makes possible the long desired 'flying cars'. This crowdfunding campaign is to prove it:

Both Russia and China are planning lander missions to the Moon as early as 2012 to test the presence of volatiles in the lunar polar regions, such as with the Luna-Glob mission. Even more important may be their in situ investigation of valuable minerals suggested by the LCROSS mission. It would be quite ironic if the U.S. LCROSS mission first demonstated the presence of these minerals but Russia and China were first to exploit them.There have been some arguments that it is important for the U.S. to investigate the retrieval of valuable rare earth elements from the Moon because of their strategic importance, while China maintains the overwhelmingly largest supply of them:

Is Mining Rare Minerals on the Moon Vital to National Security? By Leonard DavidSPACE.com's Space Insider Columnistposted: 04 October 2010 08:10 am ET""Resource knowledge is one aspect of lunar exploration that certainly drives the non-US space-faring nations. It is disappointing that planners in our [U.S.] space program have not invested in that scope or time scale," Pieters added. "Other than the flurry over looking for water in lunar polar shadows, no serious effort has been taken to document and evaluate the mineral resources that occur on Earth's nearest neighbor. Frustrating!""http://www.space.com/news/moon-mining-r ... 01004.html

See also the associated links in this article.

The U.S. not sending its own lander probes and in the near term may allow Russia and China to have abundant supplies of these minerals with the U.S. dependent on them for its own supplies. As with the plans for mining copper and gold from the sea floor, the importance of the REE's and their rising prices have led to suggestions sea floor mining should be undertaken for them as well:

That they could be financially profitable to be mined from the sea floor despite the expense raises the possibility lunar mining for them could be financially profitable if they are in the high concentrations expected.As I mentioned simple lander missions could be mounted for a few tens of millions of dollars if, for example, launched on the Russian Dnepr rocket. NASA might be disinclined to make use of this method of launching quick, low cost precursor missions. However, the U.S. could encourage business concerns to undertake such missions by offering tax breaks on the minerals returned from lunar mining. This if successful would have strategic benefits as well as making possible large scale interplanetary missions, including manned ones, from the use of the lunar propellant that would naturally become available during the lunar mining for minerals.

Bob Clark

_________________Nanotechnology now can produce the space elevator and private orbital launchers. It now also makes possible the long desired 'flying cars'. This crowdfunding campaign is to prove it:

About 12 minutes in, one of the panel members made an interesting comparison between what is considered to be a profitable mine on Earth and what the LCROSS data suggests is available near surface in some shadowed craters on the Moon. He said a mine on Earth might be profitable if you can make in the range of $150 per ton of material excavated. But judging from the LCROSS data, the minerals available in shadowed craters might value in the range of $1,000,000 per ton of excavated material. This might be sufficient justification for some mining companies to pay for a low cost exploratory lander mission. For instance the Dnepr rocket can lift 550 kg to TLI at a cost of $10 to $13 million. This might be sufficient mass for a lander with a descent rocket with just simple instruments such as a APXS and infrared spectrometers and radio transmission capability.

As a point of comparison there is a company planning to do deep sea mining starting in 2013 at a depth of 1,600 meters:

They estimate the costs would be $70 per tonne of excavated material but with the minerals valued at $1,000 per tonne.(Compare this to the estimated $1,000,000 per tonne on the Moon from the LCROSS data.) They would also use remote operated vehicles on the sea floor for the mining. The delay time in their case would only be fractions of a second though rather than the 3 seconds required from the Moon.Then we need an estimate for the costs of remote operation of mining vehicles on the Moon as there is for the sea floor.

Bob Clark

_________________Nanotechnology now can produce the space elevator and private orbital launchers. It now also makes possible the long desired 'flying cars'. This crowdfunding campaign is to prove it:

About 12 minutes in, one of the panel members made an interesting comparison between what is considered to be a profitable mine on Earth and what the LCROSS data suggests is available near surface in some shadowed craters on the Moon. He said a mine on Earth might be profitable if you can make in the range of $150 per ton of material excavated. But judging from the LCROSS data, the minerals available in shadowed craters might value in the range of $1,000,000 per ton of excavated material. This might be sufficient justification for some mining companies to pay for a low cost exploratory lander mission. For instance the Dnepr rocket can lift 550 kg to TLI at a cost of $10 to $13 million. This might be sufficient mass for a lander with a descent rocket with just simple instruments such as a APXS and infrared spectrometers and radio transmission capability.

Some more of the print and video presentations for the space manufacturing conference are online:

Elon Musk in his post Falcon 9 launch 2 Nasa TV press conference was quite clear - the Dragon is as capable, if not more so than the Orion. Cost to develop the Falcon 9 + Dragon (so far), I think, was $400M, cost to develop Orion which hasn't flown yet, $4.6B.

Also stated that the heatshield was designed for Mars speed re-rentry, unlike Orion. Also that there wasn't a huge amount of work to do to get the Dragon man rated. And that the man rated Dragon would use powered landing (parachute as safety backup), with accuracy to land on a helipad. Although Dragon is smaller, the pressurised volume is about the same as Orion.

As far as i understand future land landings will still use the parachute, no way the dragon thrusters will be capable to land the capsule on their own. Once spacex masters precise landing the will add landing gear and do land landings, thrusters will only be used for steering (and to soften the landing further?!?!).

As far as i understand future land landings will still use the parachute, no way the dragon thrusters will be capable to land the capsule on their own. Once spacex masters precise landing the will add landing gear and do land landings, thrusters will only be used for steering (and to soften the landing further?!?!).

Cheers,

c.

I'm only quoting what Musk said! IIRC he said the parachutes would be a backup to the powered landing system. That's how I understood it anyway, for the manned system at least.

That sounds familiar. I seem to remember a system mentioned that used a permanent thruster package instead of an abort tower, maybe that was intended to do powered landings? It almost seem hard to believe that would be possible from a weight standpoint though.